Man-made weather? Some say it’s just around the corner

Geogineering research looks at slowing rate of climate change

JUSTIN NOBEL

Would shooting particles, called sulfate aerosols, into the air over the Arctic in summer make things better or worse? Some suggest it might be an effective way to lower the temperature across the North. (PHOTO BY JANE GEORGE)

Winters are getting shorter, summers are becoming hotter and the ice is melting. But imagine. Is there a way to reverse all the climate changes now being experienced across the Arctic?

Imagine you step outside of Iqaluit or Arviat or Cambridge Bay one morning someday soon and see a specially-designed jumbo jet loading the sky with the kind of chemicals typically spewed from volcanoes.

Putting these particles, called sulfate aerosols, into the air over the Arctic in summer might be an effective way to lower the temperature across the North, said a study recently published in the journal Nature Climate Change.

This would happen because sulfate aerosols reflect sunlight, and less sunlight reaching the earth means colder temperatures. It also means less melting. Eventually, the sea ice in the Arctic Ocean could even build back up to the level it was 100 years ago.

“The best thing to do about climate change is to reduce emissions,” said Dr. Douglas McMartin, a climate modeler at the California Institute of Technology and co-author of the study. “But given the trajectory we’re on, we may find we need to do some form of geoengineering.”

By geoengineering, he means a way of reversing climate change through large projects that tamper with the climate.

Examples include, placing reflective structures on the land to bounce sunlight back into the atmosphere, using a “space hose” to create more clouds in the northern latitudes or loading the atmosphere with chemicals in order to lower temperatures.

McMartin said the most reasonable geoengineering solution lies in loading the atmosphere with sulfate aerosols. But while most researchers have proposed putting an equal amount of aerosols into the air across the globe, the Nature Climate Change study proposes to concentrate aerosols in specific locations, such as the Arctic.

But there could be problems.

“You can’t say we’re going to cool the Arctic, and it’s not going to have an impact anywhere else on the planet,” said McMartin. “The Arctic is too complicated.”

That’s because climate scientists are unsure just how loading the Arctic with cooling aerosols could affect weather in other parts of the globe.

And here lies one of the main problems with geoengineering: it could potentially turn into a nightmare. What if, say, a geoengineering solution cools the Arctic but causes a lack of rain and crops to fail someplace else?

There have been calls for a United Nations-led geoengineering organization that would decide what projects get to move forward. But, so far these calls have not been answered and no such organization exists.

The need for international guidelines on geoengineering were made apparent last month when the Haida people, a First Nations group that occupies a string of islands off the coast of British Columbia, decided to seed the Pacific Ocean with nearly 200 metric tonnes of iron dust and iron sulfate fertilizer.

The aim of the iron dump was to stimulate the growth of plankton, the microscopic plants that serve as food for the shrimp and smaller fish that salmon then feed on.

Satellite images show that the iron dump has indeed resulted in a 10,000-square kilometre plankton bloom, although it will take several years to see if it actually boosted salmon populations.

Meanwhile, the iron dump has many scientists up in arms.

“There’s a level at which it actually scares me that we’re comfortable with this,” said McMartin. “At some level, we’re messing with the planet and we don’t entirely understand all the details.”

For example, one downside of loading the Arctic sky with sulfate aerosols is it would produce acid rain—when normal rain combines with chemicals to make an acidic rain that then falls to earth and pollutes lakes and streams.

“You do get a very small amount of acid rain,” said McMartin. “But it is tiny compared to what we currently put into the atmosphere.”

Spraying sulfate aerosols into the upper atmosphere would also deplete the ozone layer, which protects the surface of our planet from harmful ultraviolet radiation.

“The best thing to do about climate change is reduce emissions,” said McMartin. “But in the 20 years I’ve been working on this there just hasn’t been much progress on that.”

“And I don’t have high hopes they’ll be much progress on that in the next 20 years either,” he added.